NASA's Pluto-Bound Spacecraft Has Awakened

Launched in 2006, New Horizons will awaken this weekend and approach Pluto in the spring and summer of 2015.

Update, January 29: The countdown to New Horizon's approach is officially on, with the craft already taking pictures for its closest approach in July. There's a counter on NASA's page if you need the info down to the second, but in the meantime, we should soon have images of the once-and-not-so-future ninth planet (or second dwarf planet).

The on-board telescoping camera Long-Range Reconnaissance Imager will take hundreds of snapshots of the icy world to get a better estimate on its distance. By May, we'll have a bevy of images better than any taken of the world, which is smaller than our moon. Pluto also has five known moons -- and there could be more waiting for New Horizons in its upcoming encounter. Expect new — and increasingly improving — pictures in the coming months. Come July, we'll be able to dig into the real mysteries of Pluto.

Update, January 16: New Horizons is fully awake and ready to go as it prepares for its approach to Pluto in July. Sunday, January 25, the probe will get its camera ready for the planet's first "close up."

We've known of the dwarf planet since 1930, but have never seen it beyond a blurry smudge a few pixels wide in Hubble's cameras. It's so tiny (smaller than our moon) that even the most powerful space telescopes can't resolve much detail, so the New Horizons journey, first launched in 2006, will give us that sort of view. By May, we'll be resolving Pluto at better-than-Hubble resolution. Then, we'll get the kind of exciting images Voyager sent us of the gas and ice giants in the 1970s and 1980s.

As of January 15, New Horizons has only 135 million miles to go. Not bad considering it's been on a 4.67-billion mile journey from the Earth to Pluto, with a gravity assist from Jupiter in between.

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On Saturday, the New Horizons spacecraft will awaken from slumber for the final time as it nears its final approach to Pluto—NASA's first ever visit to the formerly ninth planet, and the first time it will get clear pictures of the small, chilly world. The mission's July 2015 approach to Pluto is still seven months away, but New Horizons' science mission will officially begin on Dec. 6.

NASA launched New Horizons in 2006 and has placed it into hibernation repeatedly during its decade-long trip to the frigid outer solar system. By the time it wakes up for good on Saturday, the spacecraft will be approximately 90 light minutes away from Earth, or more than 1 billion miles from here.

This mission will mark NASA's first visit to the Kuiper Belt, a region filled with objects much like Pluto and its companion Charon: small, worlds made of methane and water ices, with faint traces of vapors comprising a tenuous atmosphere. (The abundance of those objects in the Kuiper Belt are part of the reason Pluto lost full planetary status.) New Horizons will pass within 8,509 miles of Pluto on July 14, 2015, getting by far the closest look at the dwarf planet that scientists have ever seen. The best images we have today are no more than a few dozen pixels.

What will the spacecraft see there? Voyager 2 provided some hints about Pluto back in 1989. While the probe didn't come near Pluto, it did come close to Neptune's moon Triton, which might be a cast-off from the Kuiper Belt. Triton orbits Neptune backward, which is one reason astronomers believe it to be a wandered that Neptune's gravity captures. And it appears to be composed of water and methane ices, much like Pluto is.

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We'll find out in 2015, because by May, New Horizons will have imaged Pluto in better resolution than any picture taken by Hubble. By the time of its flyby in July, scientists hope to get data that will help them finally to understand the composition of Pluto, Charon, and the four (known) other moons in the system, answering 85 years of questions that have arisen since amateur astronomer Clyde Tombaugh discovered Pluto.

Some of these questions are pretty tantalizing. For instance, there may be an ocean within the dwarf planet's icy shell, heated by potassium decay. So, despite living in the outer fringe of the solar system, Pluto may have the possibility of life, however remote and microscopic. Charon may have an ocean as well.

On its way out of the Solar System, New Horizons is likely to encounter one of a handful of new objects discovered by the Hubble Space Telescope earlier this year, and give scientists a flood of information about this icy region of space. By 2038, it will be in the outer heliosheath, preparing to leave the solar system as the Voyager probes are now doing. When it does, it will carry with it the ashes of Clyde Tombaugh.

Update: The New Horizons Twitter account posted this message at 4:03 PM on Saturday. It appears they are still awaiting a signal from the probe. Stay tuned for more updates.

She's awake by now...or she isn't. Word is coming, at the speed of light..across 3 billion miles of space, to my Maryland doorstep, tonight.

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